1. Field of the Invention
The present invention relates to an electronic component comprising a ceramic and a conductor, and particularly to an electronic component comprising a magnetic material used as a base material and a glass ceramic composite composition used in a portion having different magnetism, dielectricity and insulation.
Typical electronic components include EMI-countermeasure components such as a multilayer chip inductance device, a multilayer chip impedance device, a multilayer chip common-mode choke coil, a LC filter, and the like. The present invention can also be applied to components other than multilayer chip components, such as a multilayer substrate, a module containing a built-in component, and the like.
2. Description of the Related Art
Electronic components each comprising a magnetic material such as ferrite or the like, and a conductor used for forming a coil or the like have been conventionally known. Recently, improvements in the properties of electronic components have been required for complying with higher frequencies of electronic apparatuses.
In a multilayer chip impedance device which is a typical electronic component, it has been known that radio-frequency property deteriorates due to the stray capacitance caused between internal conductors or between an external electrode and an internal electrode, and there have been many reports of optimization of the structure of an internal conductor or an external conductor.
For example, in Japanese Patent Examined Patent Application Publication No. 62-22245, there is described a structure comprising a nonmagnetic material provided in a magnetic material, for improving the coupling coefficient of a multilayer transformer.
However, in a conventional multilayer chip impedance device, the value of stray capacitance which deteriorates the radio-frequency property is determined by the chip structure and the dielectric constant of the magnetic material used as a base material, and there is a limit in improvements of the properties by appropriately designing a conductor structure.
As disclosed in Patent Unexamined Patent Application Publication No. 2000-331831, a structure comprising a portion using a material with a low dielectric constant is considered as a countermeasure against the above-described problem.
However, in order to burn such different materials at the same time, it is necessary to alleviate the following problems:
(1) deterioration in material properties due to counter diffusion between the materials;
(2) breaking due to a difference between the shrinkage properties; and
(3) breaking due to a difference between the thermal expansion coefficients.
There has been not a known material capable of resolving the problems and producing the intended electric properties.
On the other hand, for an electronic component comprising a magnetic material, such as a multilayer transformer or the like, there have been many proposals of a structure comprising a portion using a material with low magnetism, for improving the properties. However, a material for resolving the problems has not yet been found.